BOV Troubles

For the older twin turbo B4 models

BOV Troubles

Postby Nadroj » Wed Oct 01, 2014 8:35 pm

First of all, sorry for posting about a blow off valve, and I have used the search function and couldn't find my answer :D

I purchased a GFB Deceptor Pro 2 BOV for my 02 B4, I installed it no problems but when it came time to test it, the valve wouldn't open, so I loosened off the screw for the spring to the loosest setting it would go and it still wouldn't open up under vacuum.
I jumped online and noticed they sell a softer spring so have ordered that so I figured I would chop the one in there down to at least get it to work. I had chopped about 1/4 of the spring off before it started to open under boost. Now I had the adjustment around the ball park of where I wanted it I started adjusting with the adjustment screw. I took it for a drive and when I put it in 3rd gear at low speeds and accelerate hard as the boost builds I can hear it leaking. So I figured I needed to adjust the screw in more, but when I tighten it in more the spring is too hard and when I get off boost I can hear it fluttering.

I have noticed I hear the leak when the secondary turbo kicks in, the vacuum line to the BOV is also connected to the wastegate of the primary could the primary running out of steam drop the pressure in that line causing the BOV to open?

I am stumped any help would be much appreciated (except telling me to put the stock bypass valve on :lol: )

Cheers, Jordz
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Re: BOV Troubles

Postby mwilson93 » Wed Oct 01, 2014 9:13 pm

Just don't run a bov. I would say the bov that you were supplied with may be faulty don't bother with the softer spring
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Re: BOV Troubles

Postby GONEWALKABOUT » Tue Nov 04, 2014 8:06 pm

why not attach it to the secondary, or larger turbos vacuum line?
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Re: BOV Troubles

Postby sbv » Fri Nov 07, 2014 8:27 pm

The bov vacuum line needs to run direct to the manifold. You need to remove the crossover that connects it back to the inlet pipe. This is an essential mod.

Will fix your problem.
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Re: BOV Troubles

Postby Hoody » Sun Nov 16, 2014 6:43 am

Also take the pill out of the line
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